Coseismic Deformation Mapping of the March 28, 2025 Myanmar Earthquake Using Dual-Geometry Sentinel-1 InSAR

The Mw 7.7 earthquake that struck central Myanmar on 28 March 2025 produced significant coseismic ground deformation along the Sagaing Fault, affecting major urban centers and surrounding rural areas in the Mandalay region. Rapid quantification of surface deformation is essential for understanding fault rupture behavior, guiding emergency response, and supporting post-earthquake recovery planning. To map these spatially continuous deformation fields, Interferometric Synthetic Aperture Radar (InSAR) derived from Sentinel-1 Single Look Complex (SLC) data was employed. In contrast to some regional studies that apply a strict coherence threshold to remove pixels over agricultural plains and urban fringes, this study uses a balanced coherence threshold of 0.30 during processing. This suitable approach optimizes data retention along the primary Area of Interest (AOI) covering the main rupture zone, preventing unnecessary data gaps while ensuring reliable measurements across the dynamic landscape. Wrapped interferograms show clear fringe patterns corresponding to approximately 28 mm of line-of-sight (LOS) displacement per cycle. The unwrapped results reveal displacement ranges of -0.604 m to +0.250 m in ascending geometry and -0.436 m to +0.141 m in descending geometry, with mean LOS displacements of -0.189 m and -0.063 m, respectively. Coherence analysis confirms reliable measurements along the main deformation corridor. The observed spatial variations confirm a dominant right-lateral strike-slip behavior consistent with regional tectonics. This standalone geodetic workflow offers a rapid, cost-effective, and operationally relevant framework for post-earthquake assessment and seismic hazard mitigation in data-limited environments.